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 *
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/**
 * @file modified from sf0x_parser.cpp
 * @author Lorenz Meier <lm@inf.ethz.ch>
 * @author Chuong Nguyen <chnguye7@asu.edu>
 * @author Ayush Gaud <ayush.gaud@gmail.com>
 *
 * Declarations of parser for the Benewake TFmini laser rangefinder series
 */

#include "sonar_parser.h"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <termios.h>

#include <drivers/drv_hrt.h>
#include <lib/perf/perf_counter.h>
#include <px4_platform_common/px4_config.h>
#include <px4_platform_common/module.h>
 //#define SONAR_DEBUG

#ifdef SONAR_DEBUG
#include <stdio.h>

const char *parser_state[] = {
	"0_UNSYNC",
	"3_GOT_DIST_L",
	"4_GOT_DIST_H",
	"8_GOT_QUALITY"
	"9_GOT_CHECKSUM"
};
#endif

int sonar_parse(char c, char *parserbuf, unsigned *parserbuf_index, SONAR_PARSE_STATE *state, float *dist)
{
	int ret = -1;
	//char *end;
// PX4_INFO("parse");
	switch (*state) {
	case SONAR_PARSE_STATE::STATE6_GOT_CHECKSUM:
	// PX4_INFO("STATE6_GOT_CHECKSUM");
	// PX4_INFO("%x",c);
		// if (c == 0xff) {
			*state = SONAR_PARSE_STATE::STATE2_GOT_DIST_H;
			parserbuf[*parserbuf_index] = c;
			(*parserbuf_index)++;

		// } else {
		// 	*state = SONAR_PARSE_STATE::STATE0_UNSYNC;
		// }

		break;

	case SONAR_PARSE_STATE::STATE0_UNSYNC:
	// PX4_INFO("STATE0_UNSYNC");
	// PX4_INFO("%x",c);
		// if (c == 0xff) {
			*state = SONAR_PARSE_STATE::STATE2_GOT_DIST_H;
			parserbuf[*parserbuf_index] = c;
			(*parserbuf_index)++;
		// }

		break;

	case SONAR_PARSE_STATE::STATE2_GOT_DIST_H:
	// PX4_INFO("STATE2_GOT_DIST_H");
	// PX4_INFO("%x",c);
		*state = SONAR_PARSE_STATE::STATE2_GOT_DIST_L;
		parserbuf[*parserbuf_index] = c;
		(*parserbuf_index)++;

		break;

	case SONAR_PARSE_STATE::STATE2_GOT_DIST_L:
	//  PX4_INFO("STATE2_GOT_DIST_L");
	//  PX4_INFO("%x",c);
	// 	*state = SONAR_PARSE_STATE::STATE5_GOT_QUALITY;
	// 	parserbuf[*parserbuf_index] = c;
	// 	(*parserbuf_index)++;

	// 	break;

	// case SONAR_PARSE_STATE::STATE5_GOT_QUALITY:
	// PX4_INFO("STATE5_GOT_QUALITY");
		// Find the checksum
		unsigned char cksm = 0;

		for (int i = 0; i < 2; i++) {
			cksm += parserbuf[i];
		}
// PX4_INFO("cksm=%x",cksm);
		if (c == cksm) {
			//parserbuf[*parserbuf_index] = '\0';
			//  PX4_INFO("parserbuf1=%x",parserbuf[1]);
			//  PX4_INFO("parserbuf0=%x",parserbuf[0]);
			unsigned int t1 = parserbuf[1];
			unsigned int t2 = parserbuf[0];
			t2 <<= 8;
			t2 += t1;

			if (t2 < 0xFFFFu) {
				*dist = ((float)t2) / 1000;
			}
			//  PX4_INFO("dist=%lf\n",(double)*dist);

			*state = SONAR_PARSE_STATE::STATE6_GOT_CHECKSUM;
			*parserbuf_index = 0;
			ret = 0;

		} else {
			*state = SONAR_PARSE_STATE::STATE0_UNSYNC;
			*parserbuf_index = 0;
		}

		break;
	}

#ifdef SONAR_DEBUG
	printf("state: SONAR_PARSE_STATE%s\n", parser_state[*state]);
#endif

	return ret;
}
